Water in trunk

Question - Is there supposed to be some sort of drain in the trunk well where the jack is stored? I noticed the other day about a gallon of water had collected in there in one of my cars. I can only figure it got in there from a failing left taillight gasket as to me it would be near impossible for water to go up and over the main trunk seal. So now the bottom of my jack is all rusted and I am not happy about that, but more important I want to be able to prevent water build up in the future in case replacing the tail light gasket does not fix the problem. What can I do to prevent this from happening again? Thanks!

There are many ways water gets into the trunk but lets say, for now, its the taillight. Have you tried to R&R it, bend the tabs back in place, fix the rust and seal it; I use rope caulk plus the gasket, use the dum dum next to the body side. Works wonderful.

There are drain holes on some years and they've blocked them on others.

I know the sunroof has gutters, too, but I am not exactly sure where they go.

The sun roof has 4 drain holes. The front ones have a tube going down the door post to a small drain hole in the bottom of the rocker panel.
The two rear ones run tubes back and to the side wheels in the trunk. The tubes are attached to the flap mechanism and exit through the fender behind the bumper surrounds near the side markers. If these tubes become detached and hang in the wells, they can fill up with water. The wells are all equipped with small 'D' shaped holes to let water out. More often than not, dealer undercoating plugs these up...or some boneheaded owner fills them with putty

I know the sunroof has gutters, too, but I am not exactly sure where they go.

The sun roof has 4 drain holes. The front ones have a tube going down the door post to a small drain hole in the bottom of the rocker panel.
The two rear ones run tubes back and to the side wheels in the trunk. The tubes are attached to the flap mechanism and exit through the fender behind the bumper surrounds near the side markers. If these tubes become detached and hang in the wells, they can fill up with water. The wells are all equipped with small 'D' shaped holes to let water out. More often than not, dealer undercoating plugs these up...or some boneheaded owner fills them with putty

Obviously my D shaped holes are sealed as the well holds water quite nicely. Would you suggest that I unplug this hole or is that just asking for more water to get in from driving in slush and rain. I sure wouldn't want the whole well to start rusting from the sealant being removed and water being able to constantly be in there. I still can not imagine that a gallon of water seeped in through the tail light as the car is parked in a garage most of the time. I suspect that maybe the sunroof drain is the culpret as a lot of water could potentially flow through that drain. I will investigate further!

There are many ways water gets into the trunk but lets say, for now, its the taillight. Have you tried to R&R it, bend the tabs back in place, fix the rust and seal it; I use rope caulk plus the gasket, use the dum dum next to the body side. Works wonderful.

There are drain holes on some years and they've blocked them on others.

I know the sunroof has gutters, too, but I am not exactly sure where they go.

The sun roof has 4 drain holes. The front ones have a tube going down the door post to a small drain hole in the bottom of the rocker panel.
The two rear ones run tubes back and to the side wheels in the trunk. The tubes are attached to the flap mechanism and exit through the fender behind the bumper surrounds near the side markers. If these tubes become detached and hang in the wells, they can fill up with water. The wells are all equipped with small 'D' shaped holes to let water out. More often than not, dealer undercoating plugs these up...or some boneheaded owner fills them with putty

Obviously my D shaped holes are sealed as the well holds water quite nicely. Would you suggest that I unplug this hole or is that just asking for more water to get in from driving in slush and rain. I sure wouldn't want the whole well to start rusting from the sealant being removed and water being able to constantly be in there. I still can not imagine that a gallon of water seeped in through the tail light as the car is parked in a garage most of the time. I suspect that maybe the sunroof drain is the culpret as a lot of water could potentially flow through that drain. I will investigate further!

Those drains are there to prevent water from staying in the wells...unplug them and there won't be any problems. Leave them plugged and you will get rusting problems.

I had water in the bottom of my wells when I first got the car 8 years ago; I found the drains and unplugged them...the trunk has been bone dry ever since and I have no rust.

I know the sunroof has gutters, too, but I am not exactly sure where they go.

The sun roof has 4 drain holes. The front ones have a tube going down the door post to a small drain hole in the bottom of the rocker panel.
The two rear ones run tubes back and to the side wheels in the trunk. The tubes are attached to the flap mechanism and exit through the fender behind the bumper surrounds near the side markers. If these tubes become detached and hang in the wells, they can fill up with water. The wells are all equipped with small 'D' shaped holes to let water out. More often than not, dealer undercoating plugs these up...or some boneheaded owner fills them with putty

Obviously my D shaped holes are sealed as the well holds water quite nicely. Would you suggest that I unplug this hole or is that just asking for more water to get in from driving in slush and rain. I sure wouldn't want the whole well to start rusting from the sealant being removed and water being able to constantly be in there. I still can not imagine that a gallon of water seeped in through the tail light as the car is parked in a garage most of the time. I suspect that maybe the sunroof drain is the culpret as a lot of water could potentially flow through that drain. I will investigate further!

Those drains are there to prevent water from staying in the wells...unplug them and there won't be any problems. Leave them plugged and you will get rusting problems.

I had water in the bottom of my wells when I first got the car 8 years ago; I found the drains and unplugged them...the trunk has been bone dry ever since and I have no rust.

I only thing is Peter, if you had water in there to begin with, opening the drain holes does not really fix the original leak, and Dan, you would be surprised at how much water can come in through the lites. rope caulk (dum dum is a ford name for the caulking used between seam joints on body panels) is a soft thin caulking material that never hardens, great for sealing things like these rear taillights of ours.

One thing often overlooked is the rain gutter,as Daniel mentions, when the trunk is allowed to slam up it breaks a spot weld in the gutter around the hinge area, its a small round hole in the middle of the gutterand it can fill the trunk wells in no time; you have to look close though :nerd:

I know the sunroof has gutters, too, but I am not exactly sure where they go.

The sun roof has 4 drain holes. The front ones have a tube going down the door post to a small drain hole in the bottom of the rocker panel.
The two rear ones run tubes back and to the side wheels in the trunk. The tubes are attached to the flap mechanism and exit through the fender behind the bumper surrounds near the side markers. If these tubes become detached and hang in the wells, they can fill up with water. The wells are all equipped with small 'D' shaped holes to let water out. More often than not, dealer undercoating plugs these up...or some boneheaded owner fills them with putty

Obviously my D shaped holes are sealed as the well holds water quite nicely. Would you suggest that I unplug this hole or is that just asking for more water to get in from driving in slush and rain. I sure wouldn't want the whole well to start rusting from the sealant being removed and water being able to constantly be in there. I still can not imagine that a gallon of water seeped in through the tail light as the car is parked in a garage most of the time. I suspect that maybe the sunroof drain is the culpret as a lot of water could potentially flow through that drain. I will investigate further!

Those drains are there to prevent water from staying in the wells...unplug them and there won't be any problems. Leave them plugged and you will get rusting problems.

I had water in the bottom of my wells when I first got the car 8 years ago; I found the drains and unplugged them...the trunk has been bone dry ever since and I have no rust.

I only thing is Peter, if you had water in there to begin with, opening the drain holes does not really fix the original leak, and Dan, you would be surprised at how much water can come in through the lites. rope caulk (dum dum is a ford name for the caulking used between seam joints on body panels) is a soft thin caulking material that never hardens, great for sealing things like these rear taillights of ours.

One thing often overlooked is the rain gutter,as Daniel mentions, when the trunk is allowed to slam up it breaks a spot weld in the gutter around the hinge area, its a small round hole in the middle of the gutterand it can fill the trunk wells in no time; you have to look close though :nerd:

However the water gets in; it needs a way out. With the drain cleared, there will not be any standing water trapped in the wells.
Agreed, there are several places where water can get in. As well as the tail light seals there is the rusty holes around the license plate mounting screws, the trunk lid seal, the rear window seal. Some have even pound that the trunk lid can become slightly sprung and doesn't make a good seal on the big gasket.

Finding the source of the leak often requires being locked in the trunk with a flash light while a helper aims a hose at all the suspect areas.

QuoteAndy 90 325i
Also, the antenna gasket can become hard and brittle and crack, allowing water in which will run right down the wheel well inside the trunk and into that well.

Which is exactly the problem I was having this winter, and fixed last week.
If you want to avoid irony, do not store your Bentley under a water leak if you may want to use the Bentley to try and repair said leak

Update - I took everything out of the trunk well and I could not find any D shaped area where there would have been a whole to drain the well. The way the car sits the lowest point of the well is right under the jack and there is not any indication of a hole ever being there. I could drill one, but that seems dumb if I can eliminate the source of water. The sunroof drain was connected to the flappy thingy, but I removed it and made sure that it was not plugged up and reinstalled...I do not think that that was the source of the water. I checked the hinge welds and it looks as if the left one is beginning to have some rust showing where it may be compromised, but it is really only discoloration on the paint, not full blown cancer. This could be a source of water, but I seriously doubt it would allow more than a slow drip and then the trunk carpet would be wet and discolored under that area and that is not the case here. The antenna had a new seal installed about a year ago so that is intact and functioning. When I removed the tail light I could see a definite line of rust and discolored paint indicating this is most likely the source of the water. I took a good look at the seals too and they look brittle and cracked. I found some new ones on pelican for $11 each. I am not sure if just getting new would be good enough or if doing the dum dum thing as Rick suggested might not only be cheaper, but more effective. Well, that is about it...another couple of hours fiddling with an E30. Good therapy if I might say so!

Quotewodcutr
Update - I took everything out of the trunk well and I could not find any D shaped area where there would have been a whole to drain the well. The way the car sits the lowest point of the well is right under the jack and there is not any indication of a hole ever being there. I could drill one, but that seems dumb if I can eliminate the source of water. The sunroof drain was connected to the flappy thingy, but I removed it and made sure that it was not plugged up and reinstalled...I do not think that that was the source of the water. I checked the hinge welds and it looks as if the left one is beginning to have some rust showing where it may be compromised, but it is really only discoloration on the paint, not full blown cancer. This could be a source of water, but I seriously doubt it would allow more than a slow drip and then the trunk carpet would be wet and discolored under that area and that is not the case here. The antenna had a new seal installed about a year ago so that is intact and functioning. When I removed the tail light I could see a definite line of rust and discolored paint indicating this is most likely the source of the water. I took a good look at the seals too and they look brittle and cracked. I found some new ones on pelican for $11 each. I am not sure if just getting new would be good enough or if doing the dum dum thing as Rick suggested might not only be cheaper, but more effective. Well, that is about it...another couple of hours fiddling with an E30. Good therapy if I might say so!

I use the rope caulk in addition to a good gasket, seals it forever. Don't forget to put it on the metal/body side (I use a double row around the entire perimeter), and they sell it at napa.

I sealed my tail light with black silicon on both sides of the new gasket and still had water. The source was capillary action under the gasket for the lid. I took it off and cleaned out the old sealant and replaced it using some Plumbers putty from the hardware store and most of the water issue went away. The "D" shaped hole being referred to is in the bottom flat area of the well near the front. It is actually more of a louver, stamped there facing rearward so any splash will not come in. Mine was filled with some undercoating or something. Once that was clear, I also filed a depression in the well with silicon so there would not be a puddle there too.

I get some water running down the fender well inside the trunk from some where I cannot identify on my cabrio. But, now it runs on out and does not condense on my tool kit.

QuoteBob in Everett
I sealed my tail light with black silicon on both sides of the new gasket and still had water. The source was capillary action under the gasket for the lid. I took it off and cleaned out the old sealant and replaced it using some Plumbers putty from the hardware store and most of the water issue went away. The "D" shaped hole being referred to is in the bottom flat area of the well near the front. It is actually more of a louver, stamped there facing rearward so any splash will not come in. Mine was filled with some undercoating or something. Once that was clear, I also filed a depression in the well with silicon so there would not be a puddle there too.

I get some water running down the fender well inside the trunk from some where I cannot identify on my cabrio. But, now it runs on out and does not condense on my tool kit.

QuoteBob in Everett
It appears that they do. Have not been able to find the source. Tried all kinds of things.

Bob in Everett

It would not surprise me one iota if cabrios had "special" leaks. I personally think the center brake light, mounted on top of the trunk cover with screws I believe, is another potential leak source. On my car, sometimes the former tool tray's foam rubber upper pressure pad shows a wet spot. I think the screw holes leak in a minor way.

At any rate, yesterday I washed my cabrio's back window and decided to check for trunk leaks. Yep, the tail light seals have failed. I wonder if this is the source or the occational wet carpet in the back seat.

That tail light leaking is a good possibility and may explain why my tools are all rusty. I have to clean them and put W-40 on them a couple of times a year. The foam above the tools does get wet and I have found some water in the tool tray. Have not had it dripping out much though. May have to take off the light and put some sealant on it somewhere.